This invention relates to low light level cameras, and more specifically relates to a novel camera having a plurality of axially movable intensifier assemblies which are connected in parallel with a common high voltage power supply.
Low light level cameras are well known in the art wherein a plurality of image intensifiers are connected in series with one another and to a vidicon-type tube. In such arrangements, the intensifier terminals are connected in series with one another and in series with a power supply which has an output voltage equal to the sum of the voltages required for each intensifier. Thus, if there is an assembly of three image intensifiers which each require 10,000 volts for their operation, the power supply would provide 30,000 volts in series with the intensifier assembly. The complete intensifier assembly is then potted in a common insulation medium, and then fixed to a frame. Focal adjustment for the camera is obtained by axially moving the lens in front of the intensifier assembly.
The above prior art arrangement requires a relatively high voltage power supply with attendant insulation problems, and requires focal adjustment from the lens side of the camera. Moreover, it is difficult to repair the unit since the individual intensifiers are potted together and a single, defective intensifier cannot be replaced without decapsulating the entire assembly.